Oil burner



9 R. D. SCHOENWETTER 2,532,888

OIL BURNER Filed Jan. 29, 1947 2 SHEETSSl-IEET l 'Rinhald ll fiahoenweller 1952 R. D. SCHOENWETTER 8 OIL BURNER Filed Jan. 29, 1947 2 S!-lEE1SSl-IEET 2 28 Il/I llflllhifl-klllllllll 27 39 38 Reinhold D. Schoenwalier Patented Jan. 15, 1952 OIL BURNER Reinhold D. Schoenwetter, Rosslyn, Va., assignor, by mesne assignments, to Jesse Donella, Long Island City, N. Y.

Application January 29, 1947, Serial No. 725,140

4 Claims.

This invention relates generally to oil burners and is directed particularly to the pressure atomizing type of oil burner designed particularly for use in boilers and furnaces of residence heating systems.

The present invention is directed particularly to an improvement in the head structure of the type of oil burner shown in applicants prior patents such, for example, as Patent. No. 2,319,636 of May 18, 1943, and applicants co-pending application, Serial No. 629,781, filed November 20, 1945, now Patent 2,501,414, March 21, 1950 and. a particular object of the present invention is to provide an I improved" form of flame shaping means whereby the size and shape of the flame may be controlled or regulated in accordance with the particular type of oil used.

Another object of the invention is to provide an oil burner structure and head having a removable top portion or cover formed integrally with a novelly designed flame shaping unit, whereby air introduced around and toward the axial center of a spray nozzle will be caused to move upwardly and tangentially across the axis of the spray nozzle to assume outside and above the burner head a form whereby the atomized oil combined therewith will burn in complete suspension above the head.

A still further object of the invention is to provide, in an oil burner of the type referred to, a head structure having a removable top portion or cover having a central outlet through which oil is sprayed axially from a spray nozzle, which outlet is defined by a wall having an upwardly and inwardly sloping lower portion and 0 an upwardly and outwardly sloping upper portion, which functions to guide air introduced from the sides of the nozzle, upwardly and inwardly across the axis line of the nozzle through its. contact with the lower portion andfinally with the showing of the drawings but may be changed or modified so long .as'such changes or modifications mark no material departure from. the salient features of the invention as expressed Figure 3 is a vertical section taken on the line 3-3 of Figure 1.

Figure 4 is a view in top plan of the combustion plate per se,

Figure 5 is a View of the underside of the combustion plate.

Referring now more particularly to the drawings, the numeral I0 generally designates the head structure of an oil burner unit of the type particularly described in my co-pending application previously referred to, which head includes a circular lower portion l l which is formed integrally with an air tube or conduit I2 which receives air from a suitable source, not shown, such as an air wheel or fan, to be conducted upwardly into the hollow head structure and dis-- tributed therein around the hereinafter described fuel atomizing nozzle, in a manner also to be described.

Extending from a suitable fuel source, through the air conduit, [2 is a fuel pipe line l3 which terminates in the upwardly directed atomizingnozzle supporting elbow M which is in turn supported on the axial center of the cylindrical head structure by the posts or pins l5. Upon the upper end of the elbow I4 is secured the atomizing nozzle I B, the outlet or orifice of which is directed upwardly on the axis of the head as will be readily apparent.

As shown, the nozzle I6 is of an overall diameter less than the width of the elbow H! to which it is attached, thus providing a flat shoulder l1 around the nozzle.

The head structure [0 also includes the mp1 portion H! which forms the combustion head cover, the construction of which constitutes the present invention.

As will be readily seen, the combustion head cover It is of circular form and of substantially the same overall diameter as the circular lower portion l I of the head and such cover comprises the cylindrical wall portion or skirt l9 which is formed integrally with the flat top wall portion 20 which is of relatively narrow width and in effect constitutes a narrow, inwardly extending annular rim.

The circular opening defined by the annular wall 20 is designated 2| and formed integrally with the inner edge of the wall 20 is the flame shaping flue wall which is generally designated 22.

The flue wall 22 comprises a lower portion 23 which slopes inwardly and upwardly from the edge of the. opening 21. to form the atomized fuel and air outlet openings 24. Integral with the inner edge of the inwardly inclined lower portion 23, is the upwardly and outwardly inclined upper wall portion 25 for the flue. Thus it will be seen' that the flue wall 22 is formed by joining the small ends of two hollow cone frustums.

Within the combustion head cover- P8 is located a swirl producing plate or combustion plate which is generally designated 26. This plate 26' is ofmaximum diameter materially greater than the diameter of the cover opening 2! and it has formed integrally therewith upon the top side and around its perimeter the inwardly directed spaced-,tapering lugs 21 which engageagainst the under side of the top wall 20 and. which form with such top wall the tangential air admission passages 28. CapscrewsZH or other suitable means, are employed for securing the plate 26 to the wall '26 in the-manner shown.

The center of the: plate 26- has therein the opening 30 which is defined onthe under side of the plate by the downwardly extending skirt 3| which is of a diameter to receive the nozzle l6 and rest at its bottom edge upon the shoulder I! as illustrated. This engagementof the bottom edge of the skirt 3i with the shoulder H forms a substantially airtight joint.

'E'nci'rcling the opening 3ll' 'the top of the plate is formed to provide the mound or truncated hollow cone 32 and this mound or cone is extended inwardly beyond the opening 30' to form the 'ov'erhanging flange 33 which defines-a smaller outlet opening 34. The outlet opening 34 is concentric with the discharge aperture of the nozzle and the plate opening together with the skirt portion 3| and the surrounding portions of the mound 32, form an enclosed chamber 3 5' for the nozzle tip Hi the top or outlet of which is slightly below the plane of'the opening 34, as illustrated.

The skirt 3| is provided, above the shoulder 11, with air admission ports 38, by means of which air is ad'mitted'from thehollow burner 4 head'l'into the nozzle enclosing chamber 35. Such air, admitted under pressure from the pressure source, not shown, delivering into the conduit I2, is deflected inwardly toward the axis of the nozzle by the overhanging portion 33 and accordingly, constantly sweeps the surface of the nozzle whereby to prevent the deposition of carbon on the nozzle tip when the burner flame is extinguished. I

Disposed beneath and secured to the under side of the combustion platezfi is an annular in sulation plate 3'! which is disposed concentric with the elbow M as shown, and which carries the-concentric inn r and outer current collector rings 38an'd 39,"respectively. These" rings are electrically connected with the upwardly extending terminaipost's Ml which carry electrodes M and provision is made for the positioning of these terminal posts and electrodes 4! above the combustion plate 26, by providing the combustion plate with a suitably positioned pair of apertures 42' through which the upper ends of the terminals 40 project; The electrodes are convergently related above the combustion plate and have their adjacent ends sufficiently close to the nozzle tip to ignite fuel oil ejected therefrom when an electric spark is caused to pass between the electrodes.

Electric current is transmitted to the collector rings by means of the flexible contact fingers 43 which are supported upon a suitable insulation body 44 in the proper position to have the colle'ctor rings pressed into. contact therewith When the combustion head coveris placed in position upon the lower portion H of the head in the manner illustrated. Electric current conductors 45 are electrically connected with the contact fingers and connected with a suitable source of electricpotentialfor' supplying current to the electrodes when needed.

A detailed illustration and description of the structure lying below the combustion plate 26 is not believed to be necessary in the present case since such structure is the same as that shown and described in my co-pending applicationand initself, forms no part of the present invention.-

In'the operation. of theoil' burner with a head cap or cover of the character described, the air fed under pressure through the conduit l2 into the hollow head, rises; around the combustion plate 26 and flows inwardly ac'rosszthe top surface thereof through the passages 28 being directed by' such passages substantially tangentially to the mound 32 and the. fuel: oil projected upwardly from the nozzle tip. IS. The air, divided into. a. plurality of streams by reason of its passage between the lugs 21., will. be deflected upwardly in 'asw'irling movement. partly by contact. with the mound 3'2 'and also by reason of the gradually increasing vertical space provided by the upwardly and inwardly inclined lower wall portion 23 of the flue' structure 22.

The inclination of the under surface of the flue wall portion2'3 is such as to cause the rising, swirling streams of air toimpinge the upwardly and outwardly inclined inner surface of the upper wall portion 25. Thus the air streams will be more sharply deflected upwardly and due to their swirling movement will form the flame of the burning fuel oil spray and air mixture into a tulip-shaped head and the fuel will burn in suspension entirely above the upper end of the flue wallv 22'.

In. addition to the movement of the air across the top of the combustion plate 26, some of the air in the hollow head will enter the ports 36 and flow into the chamber 35 to sweep tangentially across the tip of the nozzle. Such air flow will combine with they spraying fuel oil and will prevent the formation of a vacuum or reduced pressure area around the nozzle and over the outlet orifice thereof. Thus when the flame is shut off therewill be. no. back flow of airto draw back onto the nozzle tip any unburned oil or carbon. This will be, carried upwardly with the swiftly moving upwardly flowing air leaving the fl-ameshaping flue.

Where fuel oils of different character or of different grades are employed ahead cover having the appropriate angular relation between the wall portions 23 and 25 of the flue wall 22, will be employed to give a flame of large or small size. For example, where it is desired to reduce the size of the flame to a minimum as is necessary'in using catalytic cracked oil, the inclination of the lower wall portion is increased and the upper wall portion 25' is brought into a sharper angle or to a more nearly vertical position. Conversely where a larger flame is desired a head cover structure would be employed wherein the lower wall portion 23 has its angle reduced or flattened and the upper wall portion is inclined outwardly from the axial center to a greater extent. In other words, the production of a small flame calls for a flue wall having the angle of the inner faces of the portions 23 and 25 increased, whereas for the production of a larger flame this angle is sharpened.

I claim:

1. In an oil burner including a hollow head having a top wall provided with a circular opening, means for introducing air under pressure into the head and an oil atomizing nozzle positioned in the head to discharge oil upwardly thru the center of said opening; a flame shaping means comprising in combination, a vertically positioned circular flue wall upon said top wall coaxial with said opening, said flue wall having a lower frusto-conical portion of gradually decreasing diameter thru a part of its vertical length and an upper inverted frusto-conical portion of gradually increasing diameter thru the remainder of its length, and a horizontal plate in the head below the flue wall, said plate having a central aperture thru which said nozzle is directed, said plate having spaced elements around the periphery thereof and bridging the space between the plate and the underside of said top wall for directing the air in streams inwardly across the top surface of the plate toward the center of the head, the plate further having an inclined top surface portion around said aperture for deflecting the air streams upwardly toward the inner surface of said upper portion of the flue, and said plate having its top surface plane from the periphery thereof to said inclined surface portion.

2. In an oil burner, a hollow head designed to receive air under pressure, the head being horizontally divided to provide a top removable cover, said cover having a top wall provided with a central circular opening, said top wall being continued around said opening at an upward inclination to form an upper smaller opening and then continued upwardly and outwardly from the smaller opening forming an outwardly flaring inverted frusto-conical circular top terminal portion, an oil spray nozzle within said head below the plane of the first opening and directed upwardly to discharge oil centrally thru said openings, a plate positioned horizontally within the head with its periphery spaced from and below said top wall, a plurality of elements spaced apart around the peripheral portion of the plate and bridging the space between the plate and the underside of said top wall around the top wall opening, said plate having a central nozzle opening surrounded by an upwardly inclined surface continuation of the plate, said spaced elements providing passages for feeding air in streams across the top of the plate and said inclined surface deflecting the air upwardly along the underside of the upward inclination of said top wall for impingement against and upward deflection by the inner surface of said top terminal portion.

3. In an oil burner structure of the character described including a hollow air receiving head and an upwardly discharging oil atomizing nozzle, said head having a circular top outlet opening coaxial with the axis of the nozzle; the combination of a circular plate in the head below said opening and having a central opening in which said nozzle is positioned, means around the perimeter of the plate and bridging the space between the plate and the top of the head for directing air in streams across the top of the plate and at a tangent to the plate opening, means encircling the plate opening for deflecting the air upwardly, and a circular flue forming body forming a part of the top of the head above said outlet opening and having joined superposed converging and diverging imperforate frusto-conical wall portions disposed to first guide the upwardly deflected air along upwardly inclined swirling paths thru and across the axial center of the outlet and then redeflect the swirling air more directly upwardly from said paths around the axial center of the body.

4. In a burner of the character stated, as an article of manufacture, a combustion head comprising a cylindrical wall, a flat top wall extending inwardly from the top of the cylindrical wall and having a central opening, an upwardly and inwardly inclined imperforate frustoconical wall forming a continuation of the top wall from the edge of said opening and defining at its top edge a circular opening coaxial with and of smaller diameter than said central opening and an upwardly extending and outwardly inclined imperforate wall of inverted frusto-conical form continuing from the said top edge of the inwardly inclined wall.

REINHOLD D. SCHOENWETTER.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 720,889 Calkins Feb. 17, 1903 1,858,302 Marshall May 17, 1932 1,862,910 Schutz June 14, 1932 2,193,829 McIlvaine et a1. Mar. 19, 1940 2,204,451 Shoemwetter June 11, 1940 2,253,266 Debler Aug. 19, 1941 2,319,636 Schoenwetter May 18, 1943 2,420,598 Jackson May 13, 1947 

